1. Field of the Invention
The present invention relates to a method of forming an insulating layer pattern in a liquid crystal display which enables the establishment of an insulating layer pattern on a substrate under low temperature without the use of expensive equipment and complicated processes.
2. Discussion of Related Art
A process of fabricating a thin film transistor (hereinafter "TFT") in liquid crystal display (hereinafter "LCD") includes the steps of forming a gate insulating layer between a gate electrode and an active layer, an insulating interlayer, a passivation layer comprising a protection layer that covers the source/drain electrodes and the like. In the process, silicon oxide or silicon nitride is used for the gate insulating layer, insulating interlayer, and passivation layer.
Chemical vapor deposition(hereinafter abbreviated CVD) or thermal oxidation as a related art is preferably used for forming silicon oxide and silicon nitride as the insulation layer.
In CVD, a process chamber for maintaining a vacuum state is supplied with silicon gas in an ambient of nitrogen or oxygen, and a thin layer is formed on a substrate through decomposition and chemical reactions.
In thermal oxidation which is an open-tube reaction undertaken under atmospheric pressure without the vacuum state, silicon oxide as the insulation layer is formed by exposing silicon to oxygen gas at a high temperature of between 1000 and 1200.degree.. Thus, an insulating layer of pure quality is formed having neither ionic impurities nor defects at an interface.
As mentioned in the above explanation, an insulating layer in LCD's according to a related art is formed by CVD or thermal oxidation. Unfortunately, the CVD method requires a complicated process and highly expensive equipment for maintaining a reaction chamber in a vacuum state. Also, the thermal oxidation method requires a high temperature for forming an insulating layer and exhibits a slow growing speed of formation.